My guess is that some piece of the kernel is setting PWR_EN low (see pages 15 & 16 in the TPS65217 Datasheet). This would explain the 1 second duration of the off state. The system could restart due to PWR_EN floating high. It does not explain why connecting to the USB power prevents the random reset.
The PMIC_POWR_EN is driven by the RTC module in the AM335x (see section 20.3.3.8 in the AM335x TRM). Is there a difference in the way the 3.2 and 3.8 kernels handle the RTC or sleep modes? On Thursday, November 21, 2013 7:53:20 AM UTC-5, Antonio Cebrián wrote: > > I have captured a BBB A5B random reboot with the oscilloscope (see > attached image). > > Ch1 → VDD_3V3B (P9.4) > Ch2 → VDD_5V (P9.6) > Ch3 → SYS_5V (P9.8) > Ch4 → SYS_RESETn (P9.10) > > This confirms that the random reboot is produced by 1 second SYS_5V fall. > > Best regards. > > > > 2013/11/20 <ance...@gmail.com <javascript:>> > >> After reading the Jakub thread the new conclusion is that this seems to >> bee a hardware related problem (related to PMIC). This may explain why >> changing kernel or changing CPU frequency doesn't resolve the problem (only >> minimizes it). >> >> I will test the Jakub hardware workaround (external MOSFET) in my own >> system. >> >> About your questions: >> >> - I'm using a BBB A5B with a custom cape that includes: a LVDS converter >> for a LCD, a resistive touchscreen, a MAX3232 converter for a RS232 port >> and a buffer for some push buttons. >> >> - I have recompiled the TI 3.2 kernel (from LINUXEZSDK-BONE v06.00) to >> include the proper LCD initialization. >> >> - The system runs a Qt application with CPU load below 10%. The CPU works >> all time at default 1 GHz frequency. >> >> - I have two identical systems under test and I got one reboot each 2 to >> 3 hours but some days both systems work without reboots for 10 to 15 hours. >> >> >> Best regards. >> >> >> El miércoles, 20 de noviembre de 2013 19:33:26 UTC+1, Lei Wang escribió: >> >>> It seems that Angstrom 3.8 kernel is more robust. But I couldn't confirm >>> that it will resolve the random reboot issue. I haven't done long term >>> testing. I remember seeing someone also has problem with it. It could be >>> just that kernel is more optimized which draws less current. >>> >>> Limiting the CPU frequency only made BBB random reboot less often. I can >>> confirm that. I believe it is also related to the current draw. The slower >>> the clock the less the power is drawn from PMIC. >>> >>> By plugging in both DC power and USB cable (mini connector), it >>> increases the PMIC current capacity. PMIC has two power paths (AC->SYS and >>> USB->SYS), which reduces the stress placed on a single path (AC->SYS). I am >>> suspecting the PMIC thermal shutdown causes the random reboot. Please take >>> a look at the other thread I mentioned in a previous post. Jakub suggested >>> putting in a Mosfet to bypass VDD_5V to SYS_5V path after boot up. >>> >>> BTW, could you tell me what is your setup besides using TI prebuild >>> kernel? Are you driving a HDMI display or a LCD cape? what else do you >>> connect to the BBB? >>> >>> Thanks, >>> >>> Lei >>> >>> >>> On Wednesday, November 20, 2013 12:28:36 PM UTC-5, ance...@gmail.comwrote: >>>> >>>> I confirm that I have the same issue with a BBB A5B using TI 3.2 kernel. >>>> >>>> After reading the full thread I guess that the posible workarounds are: >>>> >>>> - Using Angstrom 3.8 kernel. >>>> - Powering the BBB from USB. >>>> - Limiting the CPU frequency. >>>> >>>> Can anybody confirm it? >>>> >>>> Best regards. >>>> >>>> >>>> El martes, 12 de noviembre de 2013 15:37:07 UTC+1, Lei Wang escribió: >>>>> >>>>> I have similar issue. I have (2) versions of BBB (A5A and A5C). They >>>>> both randomly reboot themselves while I am running TI prebuilt BBB >>>>> android >>>>> image (from a couple hours to ten to fifteen hours). When I plug in the >>>>> USB >>>>> (DC is still powered) for logging with logcat, the reboot issue seems to >>>>> disappear. >>>>> >>>>> I don't have problem with BBB Angstrom image (based on 3.8 kernel). I >>>>> don't have problem with Andrew Henderson's android image (based on 3.8 >>>>> kernel) either. >>>>> >>>>> Another issue is that when I run TI BBB android image, the clock >>>>> randomly jumps forward 2^17 seconds. This happens on both of my BBB >>>>> boards. >>>>> The problem goes away when I run Angstrom or Andrew's android. >>>>> >>>>> I suspect it has something to do with the processor, DDR3 (BBB: AM3359 >>>>> 1GHz + 512MB DDR3), the configuration, or apply workaround of errata. We >>>>> have an AM335x EVM kit (AM3359 720MHz + 256MB DDR2). I also loaded TI >>>>> prebuilt android image. I have run it for several months. It is rock >>>>> solid. >>>>> I never had problem with it. >>>>> >>>>> Here are the links to my other posts in regarding to this issue. >>>>> https://groups.google.com/forum/#!category-topic/beagleboard/advanced/ >>>>> 5qSJ4dQdar4 >>>>> http://e2e.ti.com/support/embedded/android/f/509/t/297726.aspx<http://www.google.com/url?q=http%3A%2F%2Fe2e.ti.com%2Fsupport%2Fembedded%2Fandroid%2Ff%2F509%2Ft%2F297726.aspx&sa=D&sntz=1&usg=AFQjCNFNp-bsLCgqLguXpYlSGbA7sSnOaQ> >>>>> >>>>> >>>>> >>>>> On Thursday, October 31, 2013 6:32:16 PM UTC-4, Illutian Kade wrote: >>>>>> >>>>>> And now the board won't power on from the Debug Port, but will form >>>>>> the DC jack. At this point I'm about to say "fuck this shit". >>>>>> >>>>>> On Saturday, October 5, 2013 7:12:06 AM UTC-4, Illutian Kade wrote: >>>>>>> >>>>>>> Has anyone experienced their BBB rebooting at random? >>>>>>> >>>>>>> It was running solid for two days straight and this morning it just >>>>>>> keeps rebooting. This last time the power light even went out. >>>>>>> >>>>>>> *I've checked and all cables are secured. The entire setup is >>>>>>> running of a PFC UPS; so power fluctuations shouldn't be an issue. >>>>>>> >>>>>>> *CPU doesn't seem to be under load; ~20% utilization >>>>>>> >>>>>>> *I've done a total unplug-let-sit and restart >>>>>>> >>>>>>> *From what logs I've looked through (message and kern.log) the board >>>>>>> does a total restart and loses even the date (goes form Oct 5 to Aug 26) >>>>>>> >>>>>>> *I've not made any changes other than unplugging the Syba C-media >>>>>>> USB sound card and transferring it back to my main computer after I >>>>>>> wake up >>>>>>> (BBB is doubling as a media player) >>>>>>> -This has worked for a grand total of 'uptime' 2 days and some odd >>>>>>> hours with no issues. >>>>>>> >>>>>>> ..I really hope this doesn't mean the board is defective :\ >>>>>>> >>>>>>> OS: Debian Wheezy (BBB-eMMC-flasher-debian-7.1-2013-08-26.img) >>>>>>> Power: AC Adapter >>>>>>> (http://www.adafruit.com/products/276<http://www.google.com/url?q=http%3A%2F%2Fwww.adafruit.com%2Fproducts%2F276&sa=D&sntz=1&usg=AFQjCNEvq3gmvP89fzs-F5q-Np8TKs0UdA>) >>>>>>> >>>>>>> [specifically recommended by Adafruit] >>>>>>> >>>>>> > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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